Get Back BSNL Recharge Amount, If Done Wrong or Twice

What to do for BSNL wrong recharge reversal, what happens if i done twice and how to get back, which recharged amounts of mobile number allows to reverse, and is there any charges for reversal and...

source https://bsnlteleservices.com/bsnl-wrong-recharge-amount-reversal-ctopup-sms/